Migrations and Management of the Jackson Elk Herd 19970319 030 U.S. DEPARTMENT OF THE INTERIOR NATIONAL BIOLOGICAL SURVEY I Resource Publication 199 Technical Report Series National Biological Survey The National Biological Survey publishes five technical report series. Manuscripts are accepted from Survey employees or contractors, students and faculty associated with cooperative fish and wildlife research units, and other persons whose work is sponsored by the Survey. Manuscripts are received with the understanding that they are unpublished. Most manuscripts receive anonymous peer review. The final decision to publish lies with the editor. Series Descriptions Editorial Staff Biological Report ISSN 0895-1926 Technical papers about applied research of limited scope. MANAGING EDITOR Subjects include new information arising from comprehensive Paul A. Opler studies, surveys and inventories, effects of land use on fish and wildlife, diseases of fish and wildlife, and developments AsSISTANT BRANCH LEADER in technology. Proceedings of technical conferences and Paul A. Vohs symposia may be published in this series. Fish and Wildlife Leafiet ISSN 0899-451X Summaries of technical information for readers of non­ WILDLIFE EDITOR technical or semitechnical material. Subjects include topics of Elizabeth D. Rockwell current interest, results of inventories and surveys, management techniques, and descriptions of imported fish FISHERIES EDITOR and wildlife and their diseases. James R. Zuboy Fish and Wildlife Research ISSN 1040-2411 Papers on experimental research, theoretical presentations, and interpretive literature reviews. VISUAL INFORMATION SPECIALIST North American Fauna ISSN 0078-1304 Constance M. Lemos Monographs of long-term or basic research on faunal and floral life histories, distributions, population dynamics, and EDITORIAL CLERK taxonomy and on community ecology. Donna D. Tait Resource Publication ISSN 0163-4801 Semitechnical and nonexperimental technical topics including surveys; data, status, and historical reports; handbooks; checklists; manuals; annotated bibliographies; and workshop papers. Copies of this publication may be obtained from the Publications Unit, U.S. Fish and Wildlife Service, N.W., Mail Stop: 130 Webb Building, 4401 North Fairfax Drive, Arlington, Virginia 22203, or may be purchased from the National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, Virginia 22161 (call toll free l-800-553-6847). Migrations and Management of the Jackson Elk Herd By Bruce L. Smith Russell L. Robbins U.S. DEPARTMENT OF THE INTERIOR NATIONAL BIOLOGICAL SURVEY Resource Publication 199 Washington, D.C. • 1994 Contents Page Foreword . V Abstract .. 1 Objectives . 7 Study Area 7 Methods .. 9 Definitions 9 Radio Performance 10 Monitoring with Radiotelemetry 10 Delineation of Seasonal Ranges 11 Delineation of Calving Areas . 12 Estimated Sizes and Age-Class Compositions of Herd Segments . 12 Evaluation of Harvests 12 Statistical Treatment 13 Results ......... 13 Summer Distribution . 13 Fidelity to Winter Ranges . 13 Fidelity to Summer Ranges . 14 Spring Migration 14 Fall Migration 17 Calving. 23 Natality .. 28 Harvests .. 30 Natural Mortality 32 Survival .. 34 Discussion . 34 Distribution 34 Migration . 35 Calving ... 37 Sympatry and Diseases of Wildlife and Livestock . 38 Survival ...................... 41 Harvests of Elk and Population Regulation . 41 Size and Composition of the Grand Teton National Park Herd Segment 44 Population Regulation . 45 Restoration of Historic Distributions of Elk 46 Recommended Research . 48 Recommended Management . 48 Population Management 48 Brucellosis Management 50 Acknowledgments 50 Cited Literature 50 Appendix A 54 AppendixB 55 AppendixC 56 AppendixD 61 iii Foreword The Jackson elk herd is one of the large elk herds in the Greater Yellowstone Ecosystem and has gained international recognition and caused considerable debate. The recognition is based on the long tradition ofresearch that began in 1927 with the assignment of Olaus Murie to the National Elk Refuge for the explicit purpose of conducting research on elk. Much of the data Murie collected was used in his book The elk of North America, the first comprehensive book on that topic. Russell "Buzz" Robbins assumed Murie's position of biologist with the National Elk Refuge in 1968. He conducted research on methods for improving the elk winter feeding program, the topic of considerable debate. A natural extension of that feeding program was to determine more precisely where the elk that winter on the National Elk Refuge spend summer and fall and how the timing of their migrations affect the harvest of these elk in fall. When Robbins assumed a position with the Arctic National Wildlife Refuge, Bruce Smith became refuge biologist. Since 1982, Smith has pursued research on the Jackson elk herd with candor and a special understanding of this large ungulate and its value to the various segments of the public. The Migrations and Management of the Jackson Elk Herd presents the authors' 25-year collection of data that include one of the most comprehensive sets ofavailable data on ungulate migrations. The authors integrated their own data not only with the literature but with the numerous management reports of the past 40 years. The work is an important and comprehensive analysis of the problems and management of one of the most controversial herds of ungulates in North America. John L. Oldemeyer Leader Endangered Species Research National Ecology Research Center National Biological Survey V Migrations and Management of the Jackson Elk Herd by Bruce L. Smith and Russell L. Robbins1 U.S. Fish and Wildlife Service National Elk Refuge P.O. BoxC Jackson, Wyoming 83001 Abstract. From April 1978 to April 1982, 85 adult (~2. 7 years-old) elk (Cervus elaphus nelsoni) were captured and radio-collared on the National Elk Refuge in northwestern Wyoming. Relocations with biotelemetry from 1978 to 1984 showed that the radio-collared elk occupied four distinct summer ranges: 48% summered in Grand Teton National Park, 28% in Yellowstone National Park, 12% in the Teton Wilderness, and 12% in the Gros Ventre drainage. Elk that summered in a specific range are collectively a herd segment of the Jackson elk herd. The fidelity to the summer ranges was 98%; the fidelity to the winter range at the National Elk Refuge was 97%. At least 69% of the calving by elk from all four summer ranges occurred in the Grand Teton National Park central valley. The fidelity to calving areas inversely correlated with the distance between a calving area and the National Elk Refuge winter range. The fall migration commenced in October or November, and 94% of the radio-collared elk arrived at the National Elk Refuge by 15 December. Most elk that were harvested by hunters in the park and on the National Elk Refuge during the early stages of the fall migration were from the Grand Teton National Park herd segment. From 1978 to 1984, hunters reduced the number of wintering elk on the National Elk Refuge from 8,413 to 5,010. Efforts to reduce the size of the Grand Teton National Park herd segment by hunting have been unsuccessful. However, the size of this herd segment seemingly stabilized since the late 1960s and was about 3,700 elk (2,869-4,486, 95% CI, post-hunting season) during this study. We recommend the establishment of management objectives for each of the four herd segments and an investigation of density-dependent effects on the recruitment, survival, and dispersal ofjuveniles. Reducing the number of elk in Grand Teton National Park and restoring the number and migrations of elk east of Grand Teton National Park to pre-1950 conditions are goals of the state and federal agencies that manage the elk and their habitat. Alternative management based on this research is offered to accomplish those goals. Key words: Brucellosis, Cervus elaphus, elk, harvest, management, migration, survival, Wyoming. 1 Present address: Route 2, Box 50, Elk Point, South Dakota 57025. 1 2 RESOURCE PUBLICATION 199 The management of the Jackson elk (Cervus herd winters and is supplementally fed at the Na­ elaphus) herd in northwestern Wyoming is a com­ tional Elk Refuge and at three state-operated feed plex interagency effort. The elk of the Jackson elk grounds in the Gros Ventre River drainage (Fig. 2). herd are known for their winter concentrations and The U.S. Fish and Wildlife Service and the extensive annual migrations (as long as 90 km) Wyoming Game and Fish Department work un­ between their winter and summer ranges. They der a 197 4 cooperative agreement to manage the migrate through and summer in the Bridger-Teton National Elk Refuge for a maximum of 7,500 elk, National Forest, Yellowstone National Park, Grand which is 68% of the targeted post-hunting-season Teton National Park, and scattered parcels of pri­ size of the entire Jackson elk herd. vate and state lands (Fig. 1). Some elk winter in the By the early 1900s, fewer than 50,000 elk re­ Bridger-Teton National Forest and Grand Teton mained in North America. Most were concen­ National Park, but about 90% of the Jackson elk trated in the area of Yellowstone National Park A 9-month-old elk eating alfalfa pel­ lets on the National Elk Refuge, Wyoming; March 1991. MIGRATIONS AND MANAGEMENT OF THE JACKSON ELK HERD 3 ,..._.....," .... -- Park boundaries ', - Roads ', """ -- Rivers , } I • - • - Nat. Elk Refuge <: I } ~ ~ 1 0246810- L_t\ Yellowstone Kilometers '"-'--1.,National I ---:_;--T- Park I Memoria, Parkway ~ .J Teton /., l_ Wilderness